A powerful cyclone has swept through the Bay of Bengal and made landfall in south-eastern India, with five people already killed by the force of the storm.
Hundreds of thousands of people had been evacuated in anticipation of Cyclone Hudhud, which boasts wind speeds of 120mph.
Heavy rains and gusts were reported as the "very severe storm" ripped through Visakhapatnam, the largest city in the state of Andhra Pradesh. The neighbouring state of Orissa is also on high alert.
One of those confirmed dead from the cyclone was killed by a wall collapse, while the others were hit by falling trees and masonry.
N. Chandrababa Naidu, the chief minister of Andhra Pradesh, said: "We are unable to ascertain the situation. Seventy percent of communication has totally collapsed... this is the biggest calamity.
"We are asking people not to come out of their houses, and we are mobilising men and materials immediately."
Authorities have set up 370 relief camps to house evacuees.
Officials in Orissa are desperately trying to convince members of an ancient tribe to leave their homes in the Bonda Hills, which is expected to face the brunt of the storm.
"The identified 2,000 tribal people, who must move, have never come down the hills in their lifetime," a local politician said.
Officials said four naval ships and nine air force helicopters are on standby for relief and rescue operations, while soldiers and federal rescue workers are also on hand.
The Indian Ocean is a cyclone hotspot.
Of the 35 deadliest storms in recorded history, 27 have come through the Bay of Bengal - and have landed in either India or Bangladesh.
In 1999, a cyclone devastated Orissa's coastline and killed at least 10,000 people.
While India has a poor record of response to natural calamities, it managed last October to safely evacuate nearly a million people out of the path of Cyclone Phailin, the strongest tropical storm to hit India in more than a decade.